Creatine is a naturally occurring nitrogenous compound found in the skeletal muscles of vertebrates that plays an important role in protein metabolism and other bio-chemical functions. For example, creatine is taken up into muscle cells by specific receptors and converted to phosphocreatine by creatine kinase.
Both creatine and phosphocreatine play an important role in the anaerobic production of ATP during short and intensive exertions, via the creatine kinase system. Specifically, during muscle contraction, there is an increase in the amount of phosphocreatine (which is generated from creatine) and consequently in ATP. The amount of phosphocreatine in the muscle cell determines the amount of time it takes for a muscle to recover from activity; thus, supplementing the diet with creatine can increase the concentration of phosphocreatine in muscles by 6 percent to 16 percent, with a consequent increase in the ATP turnover during physical exertion.
Creatine-containing supplements have been shown to increase lean body mass, high intensity power output, and overall physical strength. By virtue of these characteristics, creatine has met with enormous success among professional and recreational athletes, as well as professional and amateur bodybuilders, in recent years as a dietary supplement.
Increasing creatine levels in muscle through dietary supplementation has proven effective at enhancing athletic performance, increasing muscle workload and shortening muscle recovery time. In addition, there is increasing interest in creatine dietary supplements for a variety of therapeutic indications, including muscular dystrophy, cardiovascular diseases, neurodegenerative disorders, and mental retardation. The zwitterionic creatine monohydrate has been the standard creatine salt of choice for commercial creatine supplement formulations.
However, creatine supplements containing creatine monohydrate are not ideal dietary supplements due to their low aqueous solubility. In other words, relatively large doses of creatine monohydrate must be consumed with large amounts of fluid for effective use. People often experience excessive water retention (bloating), cramps, and significant gastrointestinal problems due to the large dosages. In addition, the relatively high doses of creatine monohydrate required to produce the desired biological effects suggest that the oral bioavailability of creatine monohydrate is low and that more efficient dosage forms may provide better desired results accompanied by fewer gastrointestinal side effects.
There are other known salt forms of creatine including creatine citrate (creatine effervescent) and creatine pyruvate that have been patented and marketed as improvements over creatine monohydrate. However, despite the various salt forms currently marketed, there remains a need in the art for a more improved form of creatine with improved solubility and bioavailability characteristics that can be consumed in smaller dosage forms.